Eraser.



P. H. BALDWIN.

BRASER.

APPLICATION FILED AUG. so, 1912.

Patented Mar. 24, 1914.

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FRANCIS H. BALDWIN, OF NEW ROCHELLE, NEW YORK.

ERASER.

Specification of Letters Patent.

Patented an. at, rail i.

Application filed August 30, 1912. Serial No. 717,928. i

To all whom it may concern Be it known that I, FRANCIS I-I. BALDWIN, residence and post-oiiice address 8 Centre avenue, New Rochelle, in the State of New York, have invented certain new and useful Improvements in Erasers, of which the following is a specification.

The invention relates to erasers for erasing ink, pigments or other marks from paper and other materials by attrition, and is of so simple a nature that it will be readily understood from the description of the preterable i'orms of it shown in the accompanying drawings.

The object of the invention in its pre ferred form is to provide an erasing brush of spun glass and provided with a mouthpiece adapted to confine or hold the brush so as to form one or more substantially sharp corners, adapting the brush particularly to the erasing of very minute points, and in addition preferably providing one or more straight edges and, for some uses, one or more curved edges on the exposed end of the brush.

In the accompanying drawings, Figure 1 is a side view of a complete eraser embodying my invention; Fig. 2 is another view of the same, partly in longitudinal cross section at right angles to Fig. 1; Fig. 3 is an end view of the mouth of the eraser; Fig. t is a cross section on the plane 4cl of Figs. 1 and 2; Fig. 5 is an outsideview of another form of the improvement; Fig. 6 is a longitudinal sectional View; and Fig. 7 is an end view of the mouth of the same.

In Figs. 1 to 4, B is the brush of spun glass secured in a cap or shaft C of brass or suitable material. D is a combined mouthpiece and holder for the brush, which is shown as adapted to receive the brush and its cap or shaft and to be adjusted upon the protruding end of the brush and secured in respect thereto by means of a set-screw F, as shown. The mouthpiece D may be of any suitable tubular cross section converging to the mouth, so as to support the brush at the mouth. Specifically as shown, it is of circular cross section and on one side is flattened or drawn downward at an incline D, forming a converging mouthpiece which affords one straight and one curved edge and two angles or corners for the slightly protruding end of the brush, which the mouth should fit snugly so as to confine and support the brush. The corners should be substantially sharp angles, though in manufacturing cheaply from metal it is impossible to make the angles absolutely sharp. It will be seen that the slightly protruding end of the brush presents edges corresponding with the edges of the mouth; that is to say, a straight edge, a curved edge and two sharp corners. In erasing, the brush should be held perpendicularly to the paper, so that it wears flat on its end, but when any very fine line or point is to be erased the sharp corner of the brush may be used, or a narrow line can be erased by the edges of the brush. The brush, it made of fine spun glass, may be very fine, and the sharp corner of the brush will then present, when the end of the brush is worn flat, three dihedral angles meeting at the corner in a point. It will be seen that by loosening the set-screw F the brush can be loosened to protrude more or less and the set-screw then tightened, holding it in adjustment similarly to a drawing pen.

In the form of the invention shown in Figs. 5, 6 and 7, the mouth of the converging mouthpiece H is a long and narrow rectangle, giving four dihedral angles and tour sharp points to the brush. Such a mouthpiece may be conveniently formed by compressing a tubular piece of metal on two opposite sides, as illustrated. The holder shown comprises a barrel or shank J, to which the mouthpiece is secured, and through the rear end of which is screwthreaded the adjusting screw K. The forward end of this screw may be formed with a small neck and head, as shown, which can be sprung into the rear of the cap L between three or more prongs L, as shown, so that the prongs clasp the neck and cause the cap to partake of the endwise adjustment of the screw while swiveling freely upon it. The rear end of the screw K is rigidly secured in the base of a cap or socket P which fits over the rear end of the barrel so as to be adjustable thereon with the screw, as shown. The brush M may be adjusted lengthwise by turning the cap P upon the barrel J, and when the brush is worn too short for further use the mouthpiece H can be unscrewed and the brush pulled oil? with its cap L and replaced by a new one.

In both forms of the invention it will be seen that the brushes are economically mounted in an inexpensive form of cap, so

that they can be supplied in quantities for renewals at a low figure of cost.

It will be seen that the mouthpiece H is detachable and removable from the brush 1 and the means for holding the brush, so that various mouthpieces of various cross section can be furnished with the eraser if desired. It will also be seen that the mouthpieces, as indeed is illustrated in both figures of the drawing, may converge from two opposite sides only, while being of uni= form width at right angles thereto. I find this form particularly suitable for giving a thin, wide form of brush suitable for photographers work and mechanical drawings, where it is frequently desirable to erase long, narrow rectilinear areas without causing such excessive wear of the sharp corners of the brush as would occur if the sharp corners only were used for straight-linework. Also, this form of mouthpiece is easily formed upon any tubular form of holder without crimping or converging it from all directions. I

It will be seen that my erasing brush comprises fine filaments of a hard abrasive substance, exemplified by glass as probably the best and cheapest example of such a substance; and in using the word glass in my claims I do not, of course, mean to ex clude equivalent substances.

I claim and desire to secure the following:

1. An eraser having in combination an erasing brush of glass and a mouthpiece therefor which is adjustable relative thereto and which has one or more substantially sharp corners or angles adapted to conform the side of the brush adjacent to its end to one or more substantially sharp dihedral angles forming one or more substantially sharp erasing points at the exposed end of the brush.

"2. An eraser having, in combination, an erasing brush of fine filaments of glass and a convergent mouthpiece therefor having one or more angles for confining the protruding portion of the brush to form an approximately sharp dihedral angle, whereby the said angle may form at the end of the brush a substantially pointed corner.

for adjusting the extent of protrusion of p the brush from the mouthpiece.

' 4. An eraser combining an erasing brush of fine filaments of glass and a mouthpiece therefor in which the said brush is supported, the mouthpiece having an angular mouth with one or more substantially sharp angles adapted to bear against the filaments and laterally confine and conform them into one or more substantially sharp dihedral angles and thereby adapted to-form one or more substantially sharp, hard and closely supported erasing points at the exposed end of the brush.

5. An eraser combining an erasing brush of fine filaments of glass and a cap for the brush in which the filaments are secured and a handle or holder provided with an angular mouthpiece adapted to confine and conform the brush to one or more approximately sharp dihedral angles, the said handle or holder being also provided with means for adjusting the said brush relatively to the mouthpiece, and the said cap of the said brush being provided with a detachable securing device for securing it to the said adjusting means, whereby the said cap and brush may be actuated in both directions and readily detached.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses this 29 day of August, 1912.

EDWARD G. Cox, HAROLD BINNEY.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Pat ents, Washington, D. C. 

